University of Hamburg, Director of the Psychological Institute (1916-1933)

Duke University, Lecturer and Professor (1933-1938)

Major Contribution

The Intelligence Quotient

Ideas and Interests

William Stern decided that "personalistic psychology" or individuality
was destined to be the psychological problem of the twentieth century.
He attempted to classify people according to types, norms, and aberrations.
To Stern, it was in the process of investigating individuality that the
real essence of personality and intelligence could be discovered. Stern
was influenced by the work of Binet and his studies of intelligence in
children. As a result, Stern reviewed the principle findings in the field
and developed the idea of expressing intelligence test results in the
form of a single number, the intelligence quotient.

Stern's general definition of intelligence was "a general capacity
of an individual consciously to adjust his thinking to new requirements,...a
general mental adaptability to new problems and conditions of life."
Two people could adapt to a new situation with different approaches, but
if they were equally successful they demonstrated 'teleological equivalence.'
Stern looked at individual test scores as particular "mental ages"
which could then be compared to actual "chronological ages"
to determine a degree of advancement. He took the mental age and divided
it by the chronological age, and named this ratio the intelligence
quotient.

Publication

The Psychological Methods of Intelligence Testing(1912)

General Psychology from the Personalistic Standpoint (1938)

References: 8

Image Courtesy of the Archives of the History of American Psychology, The University of Akron